The invention concerns a valve for the reverse-flow flushing of teat cups in milking machinery. It includes a housing with an interior that accommodates a moving part in the form of a rotating disk. The housing has three connections. The first connection connects with the teat cups, the second with the milk line, and the third with a reverse-flow flush line. When the valve is set for milking, the first connection communicates through it with the second connection, and the third connection is blocked. When the valve is set for reverse-flow flushing, the first connection communicates through it with the third connection, and the second connection is blocked.
A valve of this type is known from U.S. Pat. No. 4,168,677. Such a valve must prevent reverse-flow flush from leaking into the teat cups or the milk line when the valve is set for milking and is loose. This requisite is ensured in the known valve in that the housing is open to the atmosphere, allowing flush to escape when the valve leaks. It is on the other hand impossible to prevent milk from accumulating on the surface of the valve. Such an accumulation will promote the propagation of germs to the detriment of the product. It is accordingly impossible to maintain satisfactory hygiene very long without occasionally taking the equipment apart and rinsing it manually.